1. Field of the Invention
The present invention relates to a solenoid valve, particularly for heating systems of motor vehicles.
2. Disclosure Information
German Offenlegungsschrift 42 26 521 discloses a solenoid valve used for heating systems in motor vehicles. The solenoid valve includes a core, axially movable in a solenoid, which actuates, via a shaft, a valve member having two valve heads spaced apart from one another, one of which controls a forward flow and the other a return flow. When one valve head in the closed position is seated on a first valve seat, the other valve head has its supporting end up against an abutment region of a base plate having an elastic facing.
Such solenoid valves for heating systems in motor vehicles are controlled in clocked mode, that is to say, the amount of liquid flowing through the valve depends on the pulse width of the control unit of the solenoid valve. Thus the supporting end provided on one valve head strikes at regular, shorter or longer intervals against the base plate having the elastic facing. And it has been found that depending on the position where the solenoid valve is fitted, this impact causes noise which can be perceived by the occupants of the vehicle as annoying.
German Offenlegungsschrift 41 10 254 discloses a solenoid valve for hydraulic circuits in motor vehicles in which such an impact noise can be avoided by electronic control of the solenoid. This known solenoid valve thus requires a more technically complex and expensive control unit.
The object of the invention is to provide an improved solenoid valve, particularly for heating systems in motor vehicles, in which the impact noises are damped by simple mechanical means to such an extent the they are no longer perceived to be annoying.